Ariver and all of its tributaries make up a ?

The point where two air masses meet is called a

Which of the following events did not occur as a result of china’s open-door policy? a. trade between japan and china was encouraged. b. all countries were given equal access to chinese ports. c. foreign influence in china increased. d. the influence of the communist party weakened.

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks